This is a very popular retail solution to hang signage in windows, on glass doors or freezers and refrigerators. The hook works well with signage hung by wire cords. The suction cup with hook can also hold many of our Clip Strip® Merchandisers as well. It's a staple at most retail stores and offices. Use to hang open for business and closed for business signs from windows to posters, banners and inside a store or business for any sign needs off glass or even metal.